Apparatus and process for freezing ice cream



March 3l, 1942- c. F.wE|NRE|cH ETAL I v 2,278,340

APPARATUS AND PROCESS FORiFREEZING ICE CREAM Filed Feb. 25, 1940 5Sheets-Sheet l agj.

O f 3? f 5@ 35 3,@ l v Mdl 30 I .36 f g A d i y n.| i

J9 a@ lx Q? g VV|| i 1 f .2@ L 420 l 1 2? f l 1 l; t l g5 Marsh 3i,1942.,

c. F. WEINRElcH ETAL 2,278,340l l APPARATUS AND PROCESS FOR FREEZNG ICECREAM Filed Feb'. 23, 1940 March 3l, 1942. Q WEINRElCH ETAL i V2,278,340

APPARATUS AND PROCESS FOR FREEZING ICE CREAM Filed Feb. 23, 1940' 5Sheets-Sheet 3 'March 31,1942.v c. F. WEINREICH ETA; 2,278,340

March 31, 1942. c. F. wElNlElci-l `:a1-A1.. 2,278,340

APPARATUS AND PROCESS FOR FREEZING ICE CREAM Filed Feb. 25, 1940 5Sheets-Shea?l 5 7g INVENTORS:

Patented Mar. 431, 1942 UNITED STATES I PATENT ,OFFICE APPARATUS ANDPROCESS FOR FREEZING ICE CREAM Charles F. Weinreich, Des Plaines, Ill.,and A1- bert L. Voggenthaler, Cedar Rapids, Iowa, ,assignors toCherry-Burrell Corporation, Wilmington, Del., a corporation ApplicationFebruary 23, 1940, Serial No. 320,402.

- (Cl. (i2-114) l f 35 Claims.

' of carrying out the improved method.

It should, of course, be understoody that the methodand apparatus heredescribed are in'- tended primarily for use in the continuousmanufacture of ice cream. However, the apparatusI chamber before the icecream is expelled from the chamber. It has been found that in thecontinuous manufacture of ice cream it is very essential that and theprocess are not limited specically to the manufacture of ice cream.

The aspect of the present invention pertaining to the agitator andelements'thereof is disclosed and claimed in our co-pending'divisionalapplication Serial No. 323,070, filed March 9, 1940.

In the construction of ice cream freezers, and especially in theconstruction of the agitation or Whipping mechanism or elementstherefor, it is essential that the construction be of sanitary design toenable the sanitary handling ofthe perishable-foodstuffs, such as icecream, processed in the apparatus.

In many types of i-ce cream freezers provided with agitator or whippingmechanisms comprised of a plurality of relatively rotatable elements,separate drive shafts are usually provided for the separately rotatableelements and these drive shafts enter the processing chamber throughseparate openings lprovided with the conventional packing boxes andseals. In the instant-design y of the agitator or whipping mechanism,though using a plurality of relatively rotatable elements which arereadily detachable one from another,`

only one driving element .enters the freezing Achamber to provide thenecessary power to drive .a refrigerated processing chamber, togetherwith suitable quantities of gas, such as air, which are combined withthe congealed ice cream mix in nely dispersed condition during theagitating and chilling operation within the processing the refrigerationbe properly and accurately controlled and that there be sufllcientrefrigeration or cooling capacity to effect a rapid crystallization orcongealing of theice cream mix upon the refrigerated surface of theprocessing chamber.

It has also been found that the degree or extent of agitation forwhipping the combined mixtures of air, uncongealed ice cream mix andcongealed ice cream mix to produce a homogeneous mass and theperiod oftime during which such agitation and also the whipping takes place withrespect to the period of time during which the ice cream is being'processed within the processing chambenas Well as the pressure underwhich the process is carried out, are very essential and importantelements which must be vprovided for and satisfactorily performed toproduce a suitable ice cream. A suitable ice cream from the consumers aswell as from the manufacturers' standpoint possesses the qualities ofline texture, and desired richness and overrun at a temperature at whichthe product is substantially formretaining and'at which the ingredientsof the processed ice cream have substantially reached a state ofequilibrium before discharge from the processing chamber, wherebysubsequent and yfurther crystallization at the temperature' of the icecream is substantially prevented.

In some of the continuous freezers formerly used commercially, -certainadjustments could be made to enable the attainment of one or more of thedesired qualities in a commercially ,acceptable ice cream by theadjustment of the freezer to secure one or more of the necessaryoperating conditions to enable the production of such ice cream.lHowever, in none of such freezlers was it possible to attain all of thedesirable results as to the quality ofthe ice cream and as to thesatisfactory processing procedures thereof. It is also advantageous tobe able to attain these results as to quality of ice crea-m andprocessing procedure through a reasonably wide range of criticalconditions as, for example, a reason- Y ably wide 'range of freezingtemperatures, pressures, duration of Iprocessing period, and degree ofagitation, and yet in each instance, regardless of the combinationselected within these variable ranges, secure a Icompleted ice creamprod-uct of desired texture, overrun, richness and in a com- -pletedstate of processing.

The combination of ingredients united to form a commercial ice cream mixnormally produces a complicated chemical solution. The changes whichtake place in such ice cream mix during the freezing or congealing,whipping and agitating process probably are the specic reasons for andare probably specifically related to the diiculties normally incurred inthe processing of i ice cream in a mechanism in which satisfactoryyprovisions have not been made to secure the desired characteristics ofthe product as have been provided for in the apparatus constituting partof the .instant invention.

In the freezing of ice cream it is desirable to freeze as great aportion of the crystallizable material, such as water, which normallycrystallizes in the processing of ice cream, as quickly as possibleafterv the introduction thereof into the ice cream processing chamber.This prompt freezing of the available water assures the formation of avast number of infinitely small ice crystals in a minimum period oftime.

The formation of such a large number of small ice crystals from thewater available for crystallization at the time prevents the formationof large undesirable ice crystals in the icecream during the processingprocedure. To satisfactorily enable such a rapid crystallization processto produce a large number of small ice crystals, it has been founddesirable to have a substantially large refrigerating surface inproportion to the volume of ice cream mix to be congealed or cooled inthe processing'chamber. A satisfactory relation of the refrigeratingsurface in the processini;r chamber to the volume 4of ice cream mix tobe cooled, when taken in ,consideration with various other features ofthe processing procedure, has been found to be substantially of a` ratiovarying between 1:1 and 1:11/2. A processing chamber having an internaldiameter of not less than 4 inches and not greater than 61/2 inches isparticularly well suited. With such a ratio of surface to volumesomewhere within the have been held in the super-saturated solution ofviscous material at the reduced temperature to form an ice cream ofmaximum stiffness at the discharge temperature.

It is this delayed process of adjustment of the viscous material withinthe ice cream freezer which prevents the immediate extraction of thesensible as well as the latent heat from the crystallizable portions ofthe product which is introduced into the processing chamber. 'I'heextraction of such heat is, however, facilitated by the proper type ofagitation and whipping within the processing chamber.

The extraction of a suilicient quantity of heat from the ice creammixture as itis first introduced into the processing chamber immediatelybrings about the formation of the first minute ice crystals, causingthereby a further concentration of the solutions comprising thecomplicated chemical structure of the ice cream mixture as Well asbringing about a greater viscosity of the product which subsequentlytends to delay further and rapid readjustment.

The further concentration of the solution will, of course, necessitate afurther reduction of the temperature of the entire mix -within theprocessing chamber to again super-saturate the solutions to bring abouta further release of crystallizable water from' the viscous solutions.In the instant process this is attained by frequent reexposures of thevarious particles of the ice cream mixture within the processing chamberto the refrigerated walls of the chamber, thereby causing a furthercooling thereof and assuring that, upon such further cooling, thecrystals formed on the refrigerated surface will be quickly. scrapedtherefrom, resulting in the forming of ice crystals of a minute sizewhereupon the product is again intermingled and whipped. 40

above indicated range, it has been found possible,

using the presently available refrigerants, to satisfactorily cool theice cream mix within the desired period of time while it is beingprocessed within the processing chamber, as Well as to al'- low such.necessary capacity of the processing chamber to enable the satisfactoryperformance of other processing operations hereinafter lreferred tospecifically.

Ice cream mix, as commercially compounded, contains a. high percentageof solutes and the formation of a viscous compound-is the obvious resultupon the cooling of the mixture within the ice cream freezer. mixturecontaining crystallizable material dissolved therein, a point ofsuper-saturation is' quickly reached and some of the crystallizablematerial is crystallized out therefrom as lquickly.

as the particles of' the viscous compound can adjust themselves to reacha state of equilibriumjat the reduced temperature to enable the freeingof the excess crystallizable material,

However, such a process of readju'stment of the concentration of theingredients of the par- Upon the cooling of such a.

handling of the mixture within the'processlng chamber enables a morerapid completion of the chemical and physical changes taking place aswell as producing a more homogeneous product in which all of theingredients are well dispersed and in which the veslculated orincorporated air, which has been intermingled with the mix to producethe desired overrun, is dispersed in minute, uniformly distributed aircells.

The repetition of the chilling process of the various particles of themixture within the processing chamber and the alternate intermingling ofthe congealed mix with the mixture more remote from the refrigeratedsurface of the processing chamber, in which procedure a vast number ofquickly formed ice crystals aswell as minute air cells are uniformlydispersed throughout the entire product, continues the processing of theproduct within the refrigerated chamber for a sumcient period of time,under the desired con- -ditions of agitating, whipping, pressure andexproduct is discharged from the super-atmosphericprooessing chamber.However, to further enable the crystallization process taking place inthe ice cream mixture without additional cooling of the product beforedischarge from the freezer, the

product is passed through a portion of the processing chamberimmediately adjacent the dis- Such mechanical By this ing blade inrelative position'to the outer agita-v charge portgenerally indicated bythe letter A in which the product is further agitated without theextraction of any appreciable heat.

Such a process enables the processing of a mixture of ice cream mix andair through a range of relatively low temperatures to produce an icecream having form-retaining properties in which the process ofcrystallization at the temperature of the mixture within the freezer hasbeen substantially completed and in which the crystalline structure isof minute order, resulting in a nely textured product.

It is one of the principal objects of this invention to provide a novelmethod and necessary satisfactory apparatus for continuously producing,in accordance with the process just set forth, a desirable ice creamhaving predetermined overrun and maximum form-retaining hardness at thedischarge temperature corresponding to the type and degree ofprocessingto which the product has been subjected and'which product maybe produced through a variable range of low temperaturesl undersuper-atmospheric pressures,

l which will also be of' fine texture and which will have reached astate of equilibrium to prevent subsequent further crystallization ofingredients of the ice cream.

A further object of the present invention is to provide an agitator orscraper and whipping assemblage-of simple, sanitary design in which thescraper and whipping elements are detachably secured together as a unit`and are readily and easily detachable one from another, and in whichthe elements of the assemblage are removable and detachably retainedtogether and in operative position within the processingl chainberwithout the use of unsanitary mechanisms. 1

Another feature of this invention is to provide an agitator having aplurality of relatively movable members in which the movable membersrotate in concurrent direction.

An additional important feature of this invention is the provision-in anice cream freezer of a processing chamber in which the ice cream, afterbeing properly congealed and whipped, is further processed y in aportion of the processing chamber, wherein the ice cream is notsubjected to any substantial further refrigeration, to thereby permitthe further completion of the crystallization process and the reachingof a state of equilibrium in the solutions comprising the ice creammixture.

These and other objects, purposes and important features of thisinvention will be 'apparent 'to those skilled in the art from thedescription of the invention and the appended claims when read inconnection with the accompanying drawings in which:

Figure 1 is a general elevational view partially in broken away sectionshowing the general arrangement of the freezing chamber, agitator Srive,discharge connectionsand supply connec ions.

Figure 2 is a plan view of the improved scrap- Y ing blade.

Ply pumps schematically.

Figure 6 is a plan view of the outer tubular agitator element.

Figure 7 is a plan view of the improved scraptor element shownl inFigure 6.

v' Figure 8 is a perspective view of the spring ring for maintaining thedasher in assembled order.

Figure 9 is a4 plan view of the intermediate dasher element.

Figure 10 is a perspective view of displacement spider of the frontcylinder head.

Figure 11 is a plan view of the inner dasher element.

Figure 12 is a perspective view of the assembled dasher and innersectional cylinder head in relative order of assembly.

Figure 13 is a longitudinal sectional view of the front end of theassembled dasher.

Figure 14 is a longitudinal sectional view of the rear portion of theassembled dasher.

Figure 15 is a cross sectional view of the as` sembled dasher takenalong a section generally indicated by line l5-I5 of Figure 13.

Figure 16 is a cross sectional view of a modification of the dashershown in Figure 15 in cross ner dasher member taken along the lineI9--l9 of Figure 11.

Figure 20 is a cross sectional View partially in outline of the solid'inner dasher element shown in Figure 16 taken along the line 20--20 ofFigure 16.

Figure 21 is a cross sectional vievvl partially in outline of the solidinner dasher element shown in Figure 1'? takenv along the line 2I--2I ofFigure 1'7.

Referring to the illustrations showing the invention in itspreferredform,'1ike numerals being associated with like elements, 25 is a freezerbase housing a refrigerant control and circulating system 26 and anagitator and pump mechanism driving unit 21. Through driving belts 28and pulleys 29 poweris supplied to the main driving shaft 30 which isxed to a suitable pulley 3i to transmit power through any suitablearrangement of belts and pulleys to the mix pumps' 32 and 33.

The front end of the drive shaft 30 is keyed by shear pin 35 to the studshaft .34 rigidly fixed to the rear portion of the freezer agitatormechanism. The ice cream mix pumps 32 and 33 supply the ice cream mix aswell as air or other suitable gas in metered and predeterminedproportionate quantities under super-atmospheric pressure to theinterior of the processing cham'- ber or freezing tube 36 through thesupply pipe The processed icecream is vdischarged from the opposite endof the processing chamber 36 in a completely processed condition throughthe discharge conduit 38. From the discharge conduit 38 the processedice cream passes through the discharge control valve 39 to any type ofconventional can filler or package filler generally indicated by thenumeral 40. n

The ice cream mix, more commonly referred 'to as mix, is supplied to themix pumps 32 and 33 from any suitable supply chamber generallylg* theinner indicated by the numeral 4l. The air or other suitable gas issupplied to the conduit joining the pumps '32 and 33 through an air orgas valve generally indicated by the numeral 42. The op- 'eration of themix pumps 32 and 33 and the air United States supply and dischargepassages 45 and 46, respectively. The fundamental arrangement of therefrigerant jackets and supply and discharge connections and otherelements associated with the supply and accurate control of therefrigerant for use in cooling the processing chamber 36 is constructedsubstantially in accordance with the general arrangement as set forth inUnited States Patent No. 2,132,932.

It is to be noted, from an examination of Figure 5, that the refrigerantjackets 43 and 44 do not extend `through the entire length of theprocessing tube 36. essing chamber 36 at the headend thereofis notsubject to the action of the refrigerant medium in the refrigerantjacket and the ice creamv leaving the freezer will, before so leavingthe freezer, pass through a portion of the processing chamberimmediately adjacent the head end thereof in which it is furtherprocessed Without being4 subjected to further substantial refrigeration.The precise proportionate length of the lfreezing chamber which is notsubjected to refrigeration d'epends entirely upon the type of agitationto which the ice cream therein may be subjected after leaving thatportion of the freezer in which it is cooled so as to permit the furthercompletion of the crystallization process and the reaching of a state ofequilibrium within the substantially completed ice cream product.

The entire assemblage of the freezing tube 36 and refrigerant jackets 43and 44 is insulated and jacketed in any conventional manner. 'I'heentire arrangement of freezing tube or processing chamber 36 andassociated refrigerant and insulation jackets is supported upon the base25 by the refrigerant discharge conduit 46 and the extension of the reargear housing 41 which is secured in any conventional manner to the rearend plate 48 of the refrigerant jacket assemblage.

The rear head 49 of the freezing or processing tube 36 is attached tothe tube 36in any conventional manner, such as by screw threads orwelding, and is provided with a laterally extending opening D to receivethe end of the mix supply line 31. The rear head 49 is also providedwith an axial opening 5| concentric with the processing tube 36 and isprovidedv with a radial end thrust bearing 52 to support the stud shaft34 fixed to the rear portion of the ice cream freezer agitatormechanism. To seal the entrance of the shaft 34 through the bearing Aportion of the procthough they do not any convenient arrangement, such,for example, as bolts 58. The discharge conduit 38is i'lxed in anaperture in the cylinder head 51 and communicates with a dischargepassage 59 in the displacement spiderv 60 fitted into theinnerdepression of the cylinder head 51.

The discharge control valve 33 visy adapted to regulate the pressurewithin the processing chamber or freezing tube 36 by restrictingthefflowof the finished ice cream discharging from`4 the processing chamber 36through conduit 3 the finished ice cream iiows through thegccnduit 38and the control valve 39 past the' adjustable spring-biased valveplunger 62,`it tends to move the plunger 62 away from the plunger seat63, thereby moving vthe plunger 62 into a position compressing thespring 64 which normally biases the plunger 62 toward the plunger seat63. The compression of the spring 64 is adjusted by means of theadjusting screw 65.

The general construction of the freezing or processing tube, the icecream mix and air supply pumps and valves, refrigerant jacketsenveloping the processing chamber, refrigerant supply and regulatingsystem, motor drive connections for the agitator mechanism and pumps, aswell as the discharge valve and can filler, all of which have beenpreviously described, are all of a type now common in commercialconstructions of ice cream freezers. They have been here described forthe purpose of explaining the mechanism which is associated with andnecessary in the operation of the improved mechanical features of thefreezer dasher and for the satisfactory practice of the processheretofore described even constitute an essence of the invention. i

On the interior of the processing chamber 36 and extendinglongitudinally throughout the en- 'I tire length thereof is housed acompound agitator or mutator of two or more relatively movable elementsand scraping blades 66. As illustrated in Figures 2, 5 to l5, 18 and 19,the mutator or agitating mechanism is comprised of a tube-like outerelement 61 somewhat less in diameter than the internal diameter of theprocessing tube or chamber 36 and rotatively supported concentricallywithin the cylinder 36.

52 a rotary `seal generally indicated by the nul meral 53 is provided.The rotary seal, when the agitator is assembled within the processingchamber, is held in sealing position against the thrust bearing 52 by acompression spring 54.

The front end of the refrigerant jacket arrangement is closed and sealedto the processing tube or chamber 36 by a front end plate'55 to which isfastened a jacket head 56 also secured to the front end `of theprocessing tube 36 exteriorly of the refrigerant jacket. A frontcylinder head 51 for the tube 36 is securely fastened in a detachablemanner to the end plate 55 Lby In the rear vportion of the hollow outeragitator element 61 is provided a concentric tubular f element orreducing member 66 keyed to the outer agitator element 61 by keys 69 and10 which also lock the one end of the stud driving and supporting shaft34 into fixed central position in the outer end of the element 66. Onthe portion of the stud shaft 64 extending out of the element 68 isprovided .a rotary seal 59. its compression spring 54 and a key-Way forthe fracturable drive key 35 for drivingly engaging the main drive shaftof the freezer, all as previously described.

- The outer tubular agitator element 61 is pro- `vided'with four sets ofelongated apertures 1I,

each set being disposed at an angle of ninety degrees to the adjacentset and each set consisting of a plurality of elongated apertures 1|longitudinally arranged in end-to-end alinement extending substantiallythroughout the entire length of the agitator element 61.

The ice cream mix pumped to and through the processing chamber 36 bythemix pumps 32 and 33 tends to congeal and adhere to the refrigeratedsurface of the processing chamber as it passes along the slender annularpassage formed between the outer. periphery of the vouter agiatorelement 61 and the inner periphery of the tubular l locked on the studs,it is loosely retained and is capable of rocking transversely, that isto say, it is capable of movement both radially and tangentially of therotatable agitator body 61. Since l the keyhole openings in the bladeare, closer to the rear edge thereof than to the scraping edge 18thereof, the greater part of the width of the blade is located in frontof the studs and above substantial alinement with the rear edge of a rowof elongated apertures 1|.

The studs 12 may be secured to the outer rotary. element 61 in anydesired manner.

Each stud 12 has a reduced neck 13 and a head 14. 'At the one end of theouter agitator element 61 there are additional locking studs 15 having acylindrical outer end alined with the studs 12.

The scraping blades 66 are provided with keyhole openings 16 for thestudsA 12 anda circular opening 11 for the studs 15. All of theseopenings are arranged in alinement lengthwise' of the blades and theyare offset from the oppositeside of the longitudinal center line of theblades from the scraping edge 18.

The. rear edge of each scraping :blade 66 is provided with serrations19,' every other one of which is inclined at an angle to the plane ofthe blade 66 and extends from the blade toward the outer tubularagitator element 61 when the blade is mountedthereon in operativeposition. When so mounted'the blade 66 substantially overlies a row ofaperturesV 1| in the wall of the tubular outer agitator element 61.

The scraping edge 18 of the blade 66 is then substantially above thefront edge of the apertures 1| but slightly removed therefrom while theends of the inclined serrations 19 at the rear edge of the blade 66 arejust inside of the apertures 1| adjacent the rear edges thereof.-Obviously thevinclined serrations 19 will guide and direct thecongealed ice cream mixture scraped from the refrigerated wall of thechamber 86 into the hollow interior of the outer agitator element 61 theapertures 1| in the outer agitator element 61.

The pressure of the congealed material scraped from the inner peripheryof the processing chamber 36 against the under side of the scrapingblade in front of the studs in conjunction with the centrifugal forcewhen the agitator is rotating holds the scrapingr edge 18 of the bladein close contact with the refrigerated wall of the freezing chamber and,in substantial tangential relation therewith. The scraping blade ispref-` erably made ofthin non-corrosive material, such as stainlesssteel, and is suiciently flexible longitudinally and transversely topermit it to be easily mounted on or removed from the vouter agitatorelement.

The frontcr head end of the outer agitator element 61 is supported forrotation upon a centrally apertured solid spider element 80telescopically fitted into the front end of the outer element 61.

through the apertures 1|l immediately below the blade 66. The ice creammix so directed into the hollow interior of the outer agitator element61, after being thoroughly whipped while therein l-by whipping membershereinafter described,

passes out from the interior of the outer agitator element 61 throughthe two remaining sets or rows of longitudinal apertures 1| disposed atan angle of ninety vdegrees to the row of apertures 1| immediately belowthe scraping blades.

To mount a scraping blade in position on the outer agitator element 61,the round part of the keyhole openings 18 is engaged with the heads 14of the studs 12 and then .the blade is moved lengthwise to engage theelongated .parts of the keyhole openings with the necks 13 of the studs124. The openings 11 are'then engaged with the outer ends of the studs15 which hold the blade in locked position on the studs 16. with theelongatedparts of the keyhole openings engaged with the necks andbeneath the heads of the studs 12. Obviously to enable such a .mountingof the scraping blades 66 it is necessary that they be flexible topermit the essential bending incidental to such manipulation of thescraping blades- The necks 13 ofthe studs' are slightly smaller than theelongated parts of the keyhole openings 16 and they are longer than thethicknessot the blade 66 so that, when the blade is securely `peripheryof the agitating element 61.

agitator element 61 and keyed thereto by a lug 8| on the outerperiphery'of the spider 8l]l which engages the slot 82 in the end of thetubular The vspider is swiveled for rotation on the thrust ibearing 83.carried by the front stud shaft 84 which at its front free end issplined to and supported in a central aperture 85 having clutching faces86 in the front displacement spider'.

The front displacement spiderll is provided at its lower side with thedischarge aperture 59 alined with the discharge aperture in the dishedfront ycylilnder head 51 into which dished portion the displacementspider is closely fitted and supported co-axially with the processingchamber 36. The displacement spider 60 is prevented from rotating by akey-81 in the front cylinder head 51 which' engages a key-way 88 'in`the outer periphery of the displacement spider 68.

The inner end o! the stud shaft 84 is rigidly fixed to the front spider89 of the intermediate whipping or agitating element which is comprisedof a series ofglongitudinally extending beating circular formation ofuniform radial extent from the central axis of the vprocessing chamber36A which is also the axis of the agitating mechanism and are positionedslightly-within the inner The opposite ends of `the beatingv rods 98 ofthe intermediate agitator-element are fixed to an annular rear spider 9|mounted for relative rotation upon a central inwardly extending pivot 92keyed to the inner end of the centrally apertured member 68 by key 93.Intermediatev their ends the rods of the stationary interalsl mediateelement are braced by annular bracing spiders 94.

The inner reduced central portion 95 of the rear internal pivot 92 issplined to a rear spider 96 of the internal whipping or agltatin'gelement to support and rotate the same concurrently with the rotation ofthe outer dasherelement 61 to which the pivot 82 is operativelyconnected. The inner whipping or agitating element rotates in the samedirection as does the outer agitator element, both rotating relative tothe intermediate whipping or agitating element.

The inner agitator element is composed of longitudinally extendingbeating rods 91 radially disposed in triangular formation from thecentral axis of the processing chamber 36 and within'the intermediateagitating element. The front end of the beating rods 91 of the internalagitating element are fixed or mounted in an annular spider 98rotatively supported on a central pintle the stud ,shafts 84 and 34 andtheassociated ele-` outer and inner agitator elements, upon the ro-4tation of the main drive shaft 30,` will rotate together in the samedirection While the intermewith respect to one another when the freezeris ments of the agitator mechanism are positioned in spaced axialvalinement so as to permit the free .rotation one within another of therelatively rotatable elements. To prevent the separation of the elementswhen assembled as shown, a lock ring |00 is engaged in a complementaryannular groove |0|` on the outer agitator element 61. The

83 carried by the front stud shaft 84 and which is prevented from movinginwardly by abutting against the front spider 89 of the intermediatewhipping element which is permanently fixed to the inner end of thefront stud shaft 84. The

intermediate Whipping element is prevented from inward longitudinalmotion by the engagement of the rear spider 99 thereof with the elementmediate and inner agitator elements from the outer agitator element. Thedisassembly of the,h

agitator mechanism is then completed by withdrawing the inner agitatorelement from the intermediate agitator element and removal of thescraping blades from the outer tubular agitator element 61. It is to benoted that, with the exception of the scraping blades, the variousrelalock ring |00 prevents the outward movement of *2-5 the spider 80which isswiveled on the bearingtively rotatable elements of the entiredasher or agitator assembly are locked in operative position withrespect to one another by the single clip ring |00, thereby providing avery sanitary and.

simple agitator construction easy to disassemble and, whendisassembledfeasy to clean. To as-l semble the dasher or agitatormechanismY thereverse procedure of that set forthv above may befollowed.

To mount the agitator for operation within the processing chamber it isinserted thereinto a suiilcient distance so that the stud shaft 34 maybe keyed to the main drive shaft 30, as indicated in the gures. Thefront displacement spider is then placed in the front cylinder head 51with the key 81 engaged in the key-way 88 and the assembled cylinderhead 51 and displacement spiderl 60 are then placed in'position over theopen head end of the processing chamber 36 with the free end of thefront supporting shaft 84 splined to the displacement spider 60.

To secure the cylinder head 51 in place the retaining bolts 58 are thentightened to seal the processing chamber. When so assembled, the

in operation. Into and through this agitating chamber the congealedmixture scraped from the refrigerated inner periphery of the processingchamber is directed by the inclined serrated portions ofthe rear edges of the scraping blades to be agitated and blended therein to produce ahomogeneous mass.

In Figures 16 and 2O are shown views of modications of an agitatormechanismin which the inner agitator element is comprised of a solidtriangular element |03 provided with end spiders |04 having a centralsocket |05 in the front spider and a socket |06 in the rear spider forsupporting andengaging Ithe reduced portion of the rear pivot 92 insplined relation therewith while the front socket |05 rotatably engagesthe front pintle 99. l

In Figures 17 and 21 are shown views of a further modified agitatorelement in which only one whipping element is provided on the interiorof the outer tubular element 61. In this modi fication the singleinternal element i01 is of triangular cross section provided with endspiders |08. The rear end spider |08 is provided with a. socket |09 torotatably engage thenrear pivot 92 while the vfront spider |08 isprovided with a socket ||0 to engage the inner end of the front studshaft 84 in a pressed t so that the inner element |01 will be held innon-rotative relation relative to the processing chamber.

In the use of the ice cream freezing mechanism just described ingdetail,ice cream mix is conforced through the slender annular passage l formedbetween the rear portion Jof the outer agitator element 61 and therefrigerated wall of the processing chamber 36 toward the front ordischarge end of the ice cream freezer at the same pressure as justmentioned. After leaving the refrigerated portion of the processingchamber the cooled and agitated mix and air then passes into theunrefrigerated portion of the processing chamber, generally indicated bythe letter A, to be further whipped. During this whippingprocess furthercompletion of the crystallization of ice takes place.v

While passing through the ,processing chamber 36 the ice cream mixcontained in the interior of the processing chamber is of such aquantity measured in cubic inches and the refrigerated periphery of theprocessing tube 36 is of such an area measured in square inches thatthe-ratio of while being process-ed therein to a maximum stiffness andsubstantial completion of crystallization at the temperature `of thedischarged ice cream.

The reaction of the interminged ice cream mix and air as it is beingprocessed, during which time crystallizable water is crystallized andthe various solutions constituting the ice cream mix become moreviscous, yhas been set out in detail in the forepart of thisapplication. It is, however, desired to point out that the above surfaceto volume ratio which has been found to be extremely satisfactory toproduce suitable qualities` in ice cream and the relative relationsbetween the quantities of mix supplied to the processing chamber and thecapacities thereof to produce therefrom substantially form-retaining icecream of maximum stiffness in a gi'ven time and at a given temperature,all as set forth specifically above, combine to enable the production ofan the processed ice cream. This improved process permits thesubstantial completion of the crvstallization process before the icecream is discharged from the super-atmospheric pressure freezer. It isthis relation of freezing pressure, agitation, period of processing,surface to volume ratio, and maximum stiffness of product at thedischarge temperature, which is made possible by the construction of afreezer in accordance with the specifications set forth above, whenpracticing the afore-described improved process.

By this process a substantially stable ice cream of maximum stiffnessmay be produced through a reasonable range of variations in each of thecritical conditions of temperature of product, pressure of processing,period of processing and surface to volume ratio.

The foregoingdetailed description of the apparatus and process has beengiven for clearness gealing of the ice cream mix upon the freezingcylinder byv crystallizing a portion of the ice 'cream mix thereon, andscraping means within the cylinder for scraping the congealed portion ofthe icecream mix from the freezing, cylinder and directing it into awhipping mechanism, said freezing cylinder having a freezing surface inproportion to its volumetric content of ice cream mix and gas varying inratio between 1:1 and 1:11/, said means for flowing ice cream mix andsaid means for owing gas through said freezing cylinder being ofcapacities sufficient to cause the ice cream mix and gas to fl'ow undersuper-atmospheric pressurenot substantially less than fifteen pounds persquare inch gauge from the admission port to the discharge port in aperiod of time varying from oneto three minutes when producing a productof substantially form-retaining stiffness when discharged from thefreezing cylinder.

2. In an apparatus for manufacturing ice cream by the continuous method,the combination of a freezing cylinder having admission and dischargeports, means for continuously flowing of understanding only and nounnecessary limitations shall be understood therefrom. Various changesin the arrangement `of the numerous elements of the apparatus, as wellas in the steps of the process, as described to explain the invention,may be made in accordance with the cornmon knowledge of those skilled inthe art and yet come within the scope of the invention as set forth inthe appended claims.

The invention is hereby claimed as follows:

1. In an apparatus for manufacturing ice cream by the continuous method,the combination of a freezing cylinder having admission and dischargeports, means for continuously flowing metered quantities of partiallycrystallizable ice cream mix under super-atmospheric pressure to andthrough the freezing cylinder, means for continuously flowing quantitiesof gas to and through the freezing cylinder at a rate necessary toproduce the desired proportion of gas and mix in the discharged product,means at the discharge port of said cylinder to adjustably control thepressure within the cylinder, means for refrigeratingthe freezingcylinder to cause a conmetered quantities of partially crystallzable icecream mix under super-atmospheric pressure to and through the freezingcylinder, means for continuously flowing quanti ies of gas to andthrough the freezing cylinder at a rate necessary to produce the desiredproportion of gas and mix in the discharged product, means at thedischarge port of said cylinder to adjustably controlthe pressure wi hinthe cylinder, means for refrigerating the freezing cylinder to cause acongealing ofthe ice cream mix upon the freezing cylinder bycrystallizing a portion of the ice cream mix thereon, scraping meanswithin the cylinder for scraping the congealed portion of the ice creammix from the freezing cylinder and directing it into a whippingmechanism, said freezing cylinder having a freezing surface inproportionl toits volumetric content of ice cream mix and gas of a ratiovarying between lzl-and 1:11/2, said means for flowing ice cream mixandsaid means for flowing gasV throughsaid freezing cylinder being ofcapacities sufficient to cause the ice cream mix and gas to flow undersuper-atmospheric pressure not substantially less than fifteen poundsper square inch gauge from the admission port to the discharge port in aperiod of time varying from one to three minutos when producing aproduct of substantially form-retaining stiffness when discharged fromthe freezing cylinder, and a Whipping 'mechanism comprising an outerrotatable carrying member, an inner rotaiable whipping member rotatablein concurrent direction with the outer carrying member and a stationarywhipping member intermediate saidrotatable carrying member and saidinner rotatable Whipping member for uniformly dispersing the congealedportion ofthe ice cream mix with the uncongealed portion of the icecream mix within the freezing cylinder and to produce an ice cream inwhich substantially all crystallization within the ice cream mix at the`temperatureof the ice cream as it leaves the freezer has been completed.

3. A machine for processing ice cream including a refrigeratedcylindrical processing chamber, scraping and whipping means within saidchamber including a hollow, rotatable, apertured blade support formingwith the cylindrical wall of the processing chamber a substantiallyannular passage forA exposing-ice cream to the refrigerated cylindricalprocessing chamber wall, scraping .blades for directing the ice creaminto the hollow rotatable support through the apertures therein, andrelatively rotatable whipping means within said support for whippingsaid ice cream to effect a finely dispersed incorporation of the gasinto the ice cream mix.

4. The method of continuously producing ice cream which consists inrapidly withdrawing heat from a portion of a flowing stream of ice creammix and gas while passing through a. cylindrical refrigerated processingchamber containing an agitator and scraping blades to reduce thetemperature thereof to a temperature at which a substantial portion ofthe available crystallizableelements of the ice cream mix may becrystallized, directing the portions of the ice cream mix scraped fromthe refrigerated chamber by said scraping blades away from therefrigerated surface, blending said crystallized portion with a highertempcratured and substantially uncrystallized'portion of the ice cream`mix not directly exposed to the refrigerated surface to blend andequalize the temperatures thereof, causingfurther crystallization in theblended mixture by re-exposure thereof to the direct action of therefrigerating medium associated with the refrigerated chamber, andrepeating said blending operation for a sufficient period of time toenable the substantial completion of the crystallization of allcrystallizable 'lements at the temperature of the product at thecompletion of the processing operation.

5. An ice cream freezer comprising, in combination, relatively movablesurfaces defining a substantially slender flow passage, one of saidsurfaces being maintained at a freezing temperaturemeans forfiowing'metered quantities of ice cream mix and gas through said flowpassage, means for scraping congealed mix from said surface maintainedat a freezing temperature and directing it into a Whipping mechanismsubstantially equal in length to the length of the relatively movablesurfaces and in which mechanism the frozen ice cream mix and unfrozenice cream mix and the gas are whipped together in a semienclosedchamber, and discharge means insaid semi-enclosed chamber to permit thedischarge of the whipped ice cream mix and gas therefrom for re-exposureto the freezing surface.

6. An ice cream freezer comprising, in combination, relatively movablesurfaces defining a `ing said chamber, a revolvable, apertured,substantially tubular surface extending'longitudinally within saidchamber and defining with the wall of the freezing chamber asubstantially slender slender sequentially interrupted ow passage.'

only part of one of said surfaces being maintained at a freezingtemperature, means for flowing metered quantities of ice cream mix andgas through said interrupted flow passage, means for scraping congealedmix from said surfacemaintained at a freezing temperature and directingit into a Whipping mechanism in which the ice cream mix and gas areWhipped together in a semi-enclosed'chamber,'discharge means in saidsemi-enclosed chamber to permit the discharge of the whipped ice creammix and gas therefrom for re-exposure to the freezing surface, and awhipping compartment formed by the same relatively movablesurfaces andsubstantially devoid of effective refrigeration and adapted to receivematerial from said interrupted flow passage for lflow passage, agitatormeans within said substantially tubular surface, means for flowingpartially crystallizable ice cream mix and air in predeterminedproportionate quantities through said fiow space,'and scraping meanscarried on said tubular surface and extending substantially to thewalls,

of said freezing chamber for scraping congealed ice cream mix from saidtubular surface, means for causing a flow of said congealed ice creammix, uncongealed ice cream mix and air into the tubular surface throughthe apertures therein, and means for permitting the discharge of theagitated ice cream mix' and air from the iride of the tubular surfaceafter the agitation thereofy for re-exposure of the blended and agitatedmaterials to the refrigerated surface of the processing chamber.

8. In an ice cream freezer, thel combination of a cylindrical freezingchamber for continuously congealing ice cream mix and incorporating gastherein in a finely dispersed state, an inlet and an outlet in saidfreezing chamber, inner and outer members mounted to rotate within saidchamber in different paths measured radially thereof, scraping meanscarried by said outer member and extending substantially to the innerperiphery of the wall of said chamber, a stationary agitator memberintermediate said inner and outer members radially of said chamber,apertures in said outer member for the passage of ice cream mix and gasinto and out of said outer member, meansfor directing the flow ofcongealed material scraped from said freezing chamber by said scrapingblades into and through said outer'rotary member, and means for rotatingsaid rotary members for agitating the material within said freezingchamber. l

9. In a continuous freezer, the combination of a cylindrical processingchamber, means for refrigerating the peripheral wall of said chamber, atubular rotary element having means for scraping said wall, said rotaryelement being arranged to define together with said wall a slenderannular cooling passage, entrance and discharge apertures in theperipheral wall -of said tubular rotary element, means for continuallycausing ice cream mix and gas to o'w through said cooling passage undersuper-atmospheric pressure, separate means for causing the fiow ofuncongealed ice crean nix, gas and congealed ice cream mix through thetubular rotary element, and beating means within said tubular rotaryelement to ca .rse a mixing of uncongealed ice cream mix with thecongealed ice cream mix and to finely disperse and incorporatequantities of gas in minute cells within the blended ice cream mix whilethe same passes through the tubular rotary element.

10. The process of continuously manufacturing ice cream to effectsubstantially complete crystal lization in minute crystals of asubstantial portion of crystallizable materials in the ice cream mix atthe temperature of the processed material which consists and incontinuously and concurrently passing the ice cream mix and gasthrough'a processing chamber having a refrigerating medium associatedtherewith, continuously scraping crystallized ice cream mix from therefrigerated surface ofthe processing chamber, directing the scrapedaway portions of .ice

`cream mix away from the refrigerated surface and blending itwith lesscongealed portions of the mix not directly exposed to the refrigeratedsurface, causing further crystallization in the blended mixture byre-exposing the blended mixture to the direct action of therefrigerating medium associated with the processing chamber, and

repeating this procedure for a sufficient period of time to effect asubstantial completion of the crystallization of the crystallizableportion of the ice cream mix crystallizable at the temperature withinthe processing chamber.

11. lIn an ice cream freezer, the combination of a cylindricalprocessing chamber, means for refrigerating the processing chamber, anagitator member within said chamber extending substantially throughoutthe entire length thereofand tion of the portions of the ice cream mixcrystal lizable atthe temperature within the processing chamber toproduce a substantially form-retaining-ice cream having uniformlydispersed ice crystals and vesiculated'gas of predeterminedproportion-relative to the quantity of icecream mix before discharge ofthe completed ice cream from the processing chamber.

13.-'Ihe process of manufacturing ice cream `having incorporated thereina predetermined quantity of vesiculated gas consisting in causingforming with the inner periphery of said chamber surface by saidscraping blades through the agitator element at the points ofinterruption of said interrupted flow passage to be beaten and blendedby the beating means within said agitator element before the materialsdirected into a continuous flow of a mixture of predetermined quantitiesof ice cream mix and the necessary quantities of gas to be incorporatedtherein under super-atmospheric pressure through a proc-v essingchamber, subjecting the surface of the processing chamber to the actionof a refrigerant to, thereby cool the mixture, causing a portion of theicecream mix to rapidly congeal and crystallize onthe surface of theprocessing chamber, rapidly scraping off the congealed and crystallizedportion and blending it 'with the remainder of the mixture, agitatingthe entire mixture while subjecting it to continued refrigeration for aperiod sufficient to permit the substantial completion of thecrystallization of a substantial portion of the crystallized ice creammix, whipping the agitated and refrigerated mixture without furthersubstantial refrigeration under the same conditions of pressure existingin the refrigerated processing chamber, and gradually reducing thepressure upon the proi, cessed mixture during dischargethereof from thesaid agitator element are re-exposed to the refrigerated wall of theprocessing chamber.

12. The process of manufacturing ice cream having a predeterminedoverrun and in which the crystallization process is substantiallycompleted at the temperature within the processing chamber before theice cream leaves the processing chamber which consists in continuouslypassing partially crystallizable ice cream mix and gas undersuper-atmospheric pressure not substantially less than fteen pounds persquare inch gauge in predetermined relative proportions through aprocessing chamber, said processing chamber having a ratio ofrefrigerated surface measured` in square inches to volume'of ice creammix and gas measured in cubic inches varying between a range of 1:1 and1:11/2, refrigerating the processing chamber for varying thetempera-ture of the ice cream mix and gas within the processing chamberand congealing a portion of the mixture by crystallization upon theinner periphery of thev processing chamber, scraping the congealedportion of the ice cream mix from the refrigerated surface and passingit into a. beating mechanism together with. gas and the uncongealedportion of the ice cream mix, beating together the consealed ice creammix,.the uncongealed ice cream mix and the gas within the beatingmechanism, repeatedly passing the beaten mixture out of the beatingmechanism into intimate contact with the refrigeratedl surface tofurther congeal portions thereof, redirecting the further. congealedportion together with the less congealed ice cream mix and gas into thebeating mechanism for further beating, and repeating procedure for aperiod of from one to three minutes processing chamber.

14. 'Ihe process of manufacturing ice cream containing a predeterminedproportion of vesiculated gas which consists in concurrently andcontinuously flowing a mixture of partially crystallizable ice cream,mix .and gas in predetermined proportions under super-atmosphericpressure through a refrigerated processing chamber, said chamber whencontaining an agitator having a surface to volumev ratio notsubstantially greater than 1:1 and not substantially less than 1:11@scraping the congealed and crystallized portion of -the mixture from therefrigerated surface of the processing chamber and intermingling it withperiod of time to permit substantially complete crystallization of thatportion of the mixture which may be crystallized at the temperaturerWithin the processing chamber, and whipping the mixture toavoid anysubstantial amount of delayed crystallization after the mixture leavesthe ice cream processing chamber and is discharged into atmosphericpressure to produce a substantially form-retaining, completely processedice cream within the processing chamber.-

15. The process of continuously manufacturing -tities undersuper-atmospheric pressure not substantially less than fifteen poundsper square inch gauge-through a` processing chamber in which the surfaceto volume ratio is not subto thereby substantially complete thecrystalliza- 7 stantially greater than 1:1 and not substantially lessthan A1:11/2, refrigerating the processing chamber for varying thetemperature of the ice cream mix and gas within the chamber and congealing a portion of the ice cream mix by crystallization and coglipg.scraping 'the congealed .discharged into conditions of atmosphericportion from the refrigerated surface and beat,- ing it together withthe gas into the remainder of the ice cream mix during its passagevthrough the processing chamber, andagitating the entire mixture of gas,ice cream mix and crystallized portion of the mixture undersuper-atmospheric pressure vfor a period of time varying from one tothree minutes to produce an ice cream of near Vthe maximumform-retaining stiffness at the temperature of the processed ice creamhaving uniformly dispersed ice crystals and vesiculated Y gas and inwhich delay crystallization .at the temperature of the discharged icecream when sure is 'substantially prevented.

16. The process of making ice cream, sherbet or the like consisting incontinuously passing va liquid mix and gas into a closed processingchamber having a' ratio of refrigerated surface measured in squareinches to the volume of material in the processing chamber measured incubic inches not substantially greater than 1:1 and not substantiallyless than 1:15/2, maintaining said mix and gas ln said chamber under a'pressure not substantially less than fifteen pounds per` square inchgauge, controlling the quantities and.

rate of admission of the mix and gas into the processing chamber and therate of discharge of pres'- -asvasto d said chamber under a pressure notsubstantially less than fifteen pounds per.square inch gauge,continuously moving the mix and gas into and through said processingchamber under a pressure not substantially less than nfteen pounds persquare inch gauge. an adjustable means for regulating the relativeproportions of liquid mixy and gas admitted to said processing chamberto maintain thereby the desired quantity ratio between said mix andcompressed gas withinsaid chamber. said chamber having a ratio ofrefrigerated surface measured in square inches to the volume of mix andgas within said chamber measured in 'cubic inches not substantially'greater than 1:1 and not substantially less than eration, means forredirecting thefblended mass.

the desired finished product therefrom, refrlgl erating the outer wallof the processing chamber suiiicientlyl to solidify a substantialportion of said mix at the temperature within the processing chamber toform a comparatively stiff mass of the mix and vesiculated gas Vupondischarge thereof from the processing chamber, rapidly removing thesolidied material'from said refrigerated wall, directing the solidifiedmaterial into an agitating mechanism to blend it lwith the remaining mixandgas inthe chamber under conditions substantially free from furtherdirect refrigeration by contact with the refrigerated wall to envelopthe gas under pressure in flnelydispersed minute cells into the blendedmass, reexposing portions of the blended mass -to further refrigerationaction by further direct contact with the refrigerated wall to furthersolidify elements thereof, again removing the solidified portions of themix from the refrigerated wall and redirecting the same into theagitator mechanism, repeating the sequential solidiiication agi tationprocess for' a period of one to three minutes to permit the substantmattainment of a to. further refrigeratingl contact with the refrigeratedwall of the processing chamber, and ro tatable whipping means within asubstantial unrefrigerated portion of said processing chambei forfurther whipping the treated mass while substantially devoid of anyfurther refrigeratiomto permit the further completion of thecrystallization process whereby to make a homogeneous ice cream or thelike of substantially'maximum formretaining stiffness at the temperatureof the processingl chamber-in which ice cream substantially allcrystallization possibleat that temperaturehas been completed beforedischarge of the ice cream stateof equilibrium in the cooled andpartially Y crystallized mass of blended inix and gas at the temperatureof. the processing chamber. further whipping the' treatedmass in aportion of the processing chamber substantially devoid of refrigeration,and discharging the completely processed mass at a uniform rate througha conduit devo-id of refrigeration, whereby the gradual expansion of thegas cells within the vprocessed mass is permitted without rupturing thecells in a substantially completely .crystallized icecream of maximumstiness at the temperature of the processing chamber and having apredetermined overrun.

17..A machine for making ice cream. sherbe or thelike from a liquid mixand gasra processingchamber having av stationary wall. only partei-whichis subiectedtothe action of a refrigerant, means for refrigerating saidparto! the wallfto aV temperature below the crystallization temperaturelof a substantial portion of said liquid mi x ,fmeans for continuouslyand concur-` rentlydehvering said liquidmix and gas into to atmosphericpressure from thepressure frees- .ingchamben l Y 18. A machine forprocessing icecream including a cylindrical processing cylinder. a'rotatable 'agitator mechanism within said cylinder forming therewith asubstantially annular and sequentially interrupted flow e, ascraping'and whipplinkv blade carried by said agitator mechnldm' andextending substantially to Ythe processing cylinder wall throughout theentire length of the cylinder, means for effecting a continuous relstive.rotation of said agitator mechanism and said cylinder, means forintroducing a/mix and gas into said passage, means separate from saidagitator mechanism forj-forcing said mix and gas continuously throughsaid processing cylinder.

means `for changing' the temperaturen! said mix v fand gas during thepassage thereof through said processing cylinder to decrease thefluidity thereof. separate beating `means within such agitator mechanismfor agitating the mix and air separately from thev agitation.incidentsl'to the pas sage thereof through the processing cylinder andthe scrapingthereof from the refrigerated walls of the processingdirecting the mix and gas u it passes through said cylinder into thebeating housed within said agitator means.` and means for separately.whipping said material after the temperature thereof has been reduced tosubstantiallyv the discharge temperature and after thematerlal haspassed said beater mechanism, where'- by a homogeneous productof'vsubctantially comcylinder. separate means for below thecrystallization temperature of a portion of the material, the ratio ofthe chilling surface of the chamber measured in square inches to thevolume of the material in the chamber measured in cubic inches beingwithin the limits of a variable surface to volume ratio varying between1:1 and lari/2, means outside the processing chamber of a sufficientcapacity for forcing the material to flow through said refrigeratedchamber during an interval of time varying from one to three minuteswhile a suflicient portion thereof becomes congealed to transfer themass into a substantially maximum form-retaining stiffness at thedischarge temperature of the material, and a bladed 'agitator.mechanismin said chamber for scraping congealed material from said refrigeratedchamber surface and havf ing separate agitator meansextendingsubstantially throughout the entire length of said chamber for alsoagitating the material While passing through said processing chamberseparately from the agitation incidental to the fiow of the materialthrough the chamber and the scraping of the material from-the chamberwall.

20; An apparatus for refrigerating material, at least a portion of whichis crystallizable, incluaing a refrigerated chamber, means forrefrigeratinga portion of the surface of the chamber to a temperaturebelow the crystallization temperature of the crystallizable portion ofthe material, the ratio of the refrigerated chilling surface of thechamber measured in square inches to the volume 'of the material in therefrigerated portion of the chamber measured in cubic inches beingwithin the limits of a variable surface to -volume ratio varying between1:1 and 1:11/2,

means outside the processing chamber of a. suiil` cient capacity forforcing the material to flow frigerate'd portion4 of the processingchamber and the scraping of the material from the refrigerated portionof the walls of 'the chamber, and agitating means in a portion of saidchamber substantially devoid of 'eective refrigeration adapted toreceive material from the refrigerated portion of the processing chamberfor further agitating the material when substantially free of the effectof further refrigeration.

21. In an apparatus for manufacturing ice cream by the continuousmethod, the combination of a freezing cylinderv having admission anddischarge ports, means for continuously flowing metered quantities ofpartially crystallizable ice cream mix under super-atmospheric pressureto and through the freezing cylinder, means for continuously flowingquantities of gas to and through the freezing cylinder ata ratenecessary 76 to produce the desired proportion of gas and mix in thedischarged product, means at the discharge port of said cylinder toadjustably control the pressure within the cylinder, means forrefrigerating the freezing cylinder to cause a. congealing of the icecream mixupon the freezing cylinder by crystallizing a portion of theice cream mix thereon, and scraping means within the cylinder forscraping the congealed portion of the ice cream mix from the freezingcylinder, said freezing cylinder having a freezing surface -inproportion to its volumetric content of ice cream mix and gas varying inratio between 1:1 and 1:11@ said means for flowing ice cream mix andsaid means for flowinggas through said freezing cylinder being ofcapacities suflicient toA cause the ice cream mix and gas to ow undersuper-atmospheric pressure not substantially less than fifteen poundsper square inch gauge from the admission port to the discharge port in aperiod of time varying from one to three minutes when producing aproduct of desired stiffness when discharged from the freezing cylinder.

22. The method of continuously producing ice cream according to claim 4in which said processing chamber hasan internal surface to volume rationot substantially greater than 1:1 and not 'substantially less than1:11/2.

23. 'I'he method of continuously producing ice cream according to claim4 in which said processing chamber has an internal surface to volumeratio not substantially greater than 1:1 and not substantially less than1:11/2 and which processing chamber comprises a cylinder, the internaldiameter of which is not less than four inches and not greater than sixand one-half inches.

24. In an apparatus for manufacturing ice cream by the continuousmethod, the combination of a freezing cylinder having admission anddischarge ports, means for continuously owing me,- tered quantities ofpartially crystallizable ice cream mix under super-atmospheric pressureto andl through the freezing cylinder, means for continuously fiowingquantities of gas `to and through the freezing cylinder at a ratenecessary to produce the desired proportion of gasand mix in thedischarged product, means at the discharge port of said cylinder toadjustably control the l pressure within the cylinder, means forrefrigerating the freezing cylinder to cause a congealing of the icecream mix upon the freezing cylinder by crystallizing a portion of theice cream mix thereon, and scraping means within the cylinder forscraping the congealed portion of the ice cream mix from the freezingcylinder, said freezing cylinder having a'freezing surface in proportionto its volumetric content of ice cream mix and gas varying in ratiobetweenl 1:1 and 1:11/2, said means for Aflowing ice cream mix and saidmeans for owing gas through said freezing cylinder being of capacitiessumcient to y six and one-half inches and which chamber when containing'an agitator hase. vratioof surface to unoccupied volume notsubstantially greater aan 1;-1 and not substantiauy 1ess than 1:15a. 28.An apparatus for manufacturing ice cream according to claim 21 whereinthe internal diameter' of said freezing cylinder is not less than eterof said freezing cylinder is not less than four inches and not greaterthan six and one- Avhalf inches.

28. 'I'he process l.of manufacturing ice cream tion and blendingit withthe remainder of the mixture;l agitating the entire mixture whilesubaccording to claim 12 in which saidprocessing chamber comprises acylinder, the minimum internal diameter of which is not less than f ourinches and the maximum internal diameter of ,which is not greater thansix and one-half inches.

29. An. apparatus for manufacturing ice cream .according to. claim 21 inwhich the 'internal diameter of said freezing cylinder is not less thanfour inches and not greater than six and onehalf inches and in which thefreezing cylinder has an internal refrigerated surface measured insquare inches in proportion to its internal lvolumetric capacitymeasured in cubic-inches when devoid of scraping and whipping mecha-,-nisms varying in ratiobetween 1:1 and 1:15/2.-

30. The process of manufacturing ice cream according to claim 12 inwhichy said processing chamber has an internal diameter of not lesslthan four inches and not greater than six andV one-half inches and arefrigerated surface measured in square inches in proportion tovolumetric capacity measuredin cubic inches when devoid of scraping andwhipping mechanisms varying in 31. The process of manufacturingsemi-solid, edible foodstuffs having incorporated therein apredetermined. quantity of vesiculated gasconsisting incausing acontinuous ilow of a mixture of. predetermined-quantities of theconstituents of said edible foodstuffs and the necessary quanvtitles ofgas to be incorporated therein 4under super-atmospheric pressure througha temperature lowering processing chamber, subjecting the surface ofsaid temperature lowering processing chamber to the action of arefrigerant to chill the and agitating mech Jecting it to continued'refrigeration for a period sufficient to permit the substantialcompletion of the crystallization of a substantial portion of theproce'ssed mixture during the dischargethereof from said processingchamber.

32. The process of manufacturing semi-solid,

edible foodstuffs according to claim 31 in which said processing chamberwhen devoid of scraping and blending means has-a ratio of refrigeratedsurface measured -in square inches to volume measured in cubic inchesnot substantially greater than 1:1 and not substantially less than 1:15aand 'which processing chamber has an internal diameter of not less thanfour inches and not greater than six and one-half inches.

33. The process of manufacturing ice cream according to claim 14 inwhich said refrigerated processing chamber when containing an agitatorhas a surface to volume ratio not -greater than 1:1 and not less than13%.

34..The.'process of manufacturing semi-solid,

edible foodstuffs according tocclaim 31 in which 30' said processingchamber whenfdevoid of scraping and blending means has a' ratio ofrefrigerated surface measured in square inches to volume measured incubic inches not substantially greater than 1:1 and not substantiallyless than lzll, which processing chamber has an internal diameter of notless than four inches and not great- Y er than six and one-half inchesand which processing chamber containsl scraping, blending blending ofthe produ t being processed is produced by positively anrelativelyrotating some of, the elements of said scraping, blending andmixture passing therethrough,causing a-portion of said mixture torapidly congeal and crystalline on the surface of said processingchamber, rapidly scraping oif the cong'ealed and crystallizedporagitating mechanisms -with respect toother elements of s'aidmechanisms.

35. An apparatus for manufacturing ice cream according to claim 24 inwhich said freezing cylinder has an internal diameter of not less thanfour inches and not greater ythan six and onehalf inches. v

' CHARLES l". WEINREICH.

ALBERT L. VOGGENTHALER.'

ms in which agitation andl

